Romance takes enough of a roughing-up in “Ring Round the Moon” that the ring in the title just might be a shiner.

But no black eyes in sight for Moonlight’s slyly seductive staging of the Jean Anouilh play. This show just shines.

It happens once in a (black and) blue moon that a single production puts so many winning performances onstage. Maybe just as rare, even at our town’s big regional theaters, is to see a 15-member cast in a show that’s not a musical.

So give credit to Moonlight (which put the show together with help from an NEA grant) for defying the vogue to downsize with this sumptuous production, and to director Jason Heil for deftly matchmaking his sprawling cast with this prickly, dyspeptic French love story.

Before even talking plot, a bouquet of posies (emphasis on the “pose”) to Francis Gercke and Jessica John, who turn in an absurdly mannered tango (choreographed to perfection by Colleen Kollar Smith) that’s one of the show’s most entertaining moments. So you think you can dance? Try doing it while chewing on mouthfuls of Anouilh’s oddball, stick-in-the-craw dialogue.

“Ring Round the Moon,” first staged in 1947, is translated from the French by Christopher Fry. As its story of twin brothers and a pending wedding unfolds, it becomes clear that not all the dialogue has a precise English analog. Yet you still get the general sense when the shrewd, no-nonsense Madame Desmortes (Jill Drexler, wonderfully bracing and funny) barks at her nephew: “Stop behaving like a cul-de-sac.”

There’s also a lyricism in the language that Heil and Co. clearly have taken pains to preserve; the mention of how the “first carriages are grinding gravel in the drive” as a grand party is about to begin, or of how a delicate white gown resembles “the smoke of bonfires.”

The play is split into three acts (running close to three hours altogether), and the first one demands patience, as the characters’ complex relationships are explained. Anouilh also is not the sort of playwright to coddle an audience; his blithe expectation that you’ll keep up seems embodied in the brash Hugo, the play’s main character.

Hugo’s chief ambition is to sabotage the wedding of his hopelessly weak-kneed brother, Frederic, to the tough, scheming Diana (Frances Anita Rivera, elegant and engaging, with a Gwyneth Paltrow vibe). So he brings in a dancer named Isabella (Mary Bogh) to pose as the niece of family friend Romainville (Danny Campbell) and lure Frederic away.

And now it can be told: The actors playing the twins are (spoiler alert!) ... actually a single actor, Howard Bickle, although a Horace Bickle is cutely credited in the program. Bickle delineates the two so expertly, though — from Frederic’s shuffling walk to the way, when Hugo apologizes, that he looks as if he just bit into a bug in his baguette — that the gambit never seems gimmicky.